Earth-thawing apparatus.



No. 64l,772. Patented Jan. 23, I900. A. HEITZELMANN. EARTH THAWING APPARATUS.

(Application filed July 25, 1898.)

(No Model.)

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N0. 64!,772. Patented Jan. 23, I900. A. HEITZELMANN.

EAR-TH THAWING APPARATUS.

(Application filed July 25, 1898.)

(No Model.)

2 Sheets-Sheet 2 H a h :11

L NITED I STATES PATENT FFICE.

EARTH-THAWING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 641,772, dated January 23, 1900.

Application filed July 25, 1898.

T0 at whom it may concern.-

Be it known that I, ALVIE HEITZELMANN, a citizen of the United States, and a resident of the city and county of San Francisco, in the State of California, have invented a new and useful Earth-Thawing Apparatus, particularly described in the following specification and illustrated in the accompanying drawings, which are referred to herein.

This invention is designed for the especial use of placer-miners in countries where the ground is frozen the whole year round or for any considerable length of ti me-for instance, in Alaska and in the Klondike district and Northwest Territories, along the banks of the Stewart and Indian rivers, and other tributaries of the Yukon.

The object of it is to provide an earththawer composed of simple parts that can be made most anywhere or which at least can be packed and transported with ease, so that the same will be available in the remotest places.

A further object is to have an apparatus of this kind which is economical to use and so built that with it the work of mining in frozen ground can be carried on on any scale, whether small or large.

Referring now to the drawings, Figure 1 is an elevation, partly broken and in section, of the entire apparatus. Fig. 2 is a top plan of the construction represented by Fig. 1. Fig. 3 is a sectional view of part of a mining-shaft, illustrating how the apparatus is used therein when drifting. Fig. 4 is a perspective view of a stove of peculiar construction, which constitutes one of the main parts of the apparatus. Fig. 5 is a detailed view of a special form of pipe-joint used in connecting the different parts of the apparatus together. Fig. 6 is a sectional view of the stove, showing the same and the grate in horizontalposition.

Similar letters and numerals refer to similar parts throughoutthe several figures. I

The invention consists, essentially, of two partsviz., a stove A and an air-heater B, constructed and combined for joint action on the ground to be thawed out.

The stove Ais made of light plates of metal, such as cast-iron or steel, which are joined together by means of lugs O and bolts D. Five such plates are used, two for the front and back, two more for the right and left ends,

- is secured to it by a pivot L Serial No. 686,835. (No model.)

and one for the top, the same being numbered, respectively, 1, 2, 3, 4, and 5 in the order named. The top 5 is formed with a suitable aperture in the middle, through which sticks of fire-wood or other fuel can be introduced, and this aperture is closed by a hinged piece or cover numbered 5. A similar aperture for a similar purpose is also made in the end marked 3, and this is likewise covered by a hinged piece numbered 3 The bottom of the stove is left open in order that the flame from the fuel burned in it may be brought into immediate contact with the frozen ground. A grate E is employed to hold the fuel in place, and this grate can be set and used in difierent positions, as hereinafter described. An out let F for the smoke is provided in the fixed portion of the top 5, near the right end 3, and

in this is fitted a stovepipe G. In the opposite end 4 on the left is a draft-hole H, closed by a slide J. The stove thus formed can be of any suitable size, though ordinarily it will be made about three feet long, two feet wide, and one foot and a half high. I prefer making it also two inches wider at the bottom than at the top, so that it will taper a little'toward the top.

The stove-plates aforesaid, including the hinged portions thereof, are covered with sheets of asbestos or made double, with about an inch of space between, which is to be filled with asbestos, ashes, or some other substance that is a non-conductor of heat, as shown at K, Fig. 3. This space may be filled in the same way as the space in' the walls of an icechest. The idea is to hold, confine, and re fleet the heat to a given point in burning or thawing out the ground when sinking min= ing-shafts and running drifts.

To the cover 5 is attached a latch L,which made to swing under a catch or hookL fixed to the front edge of the top 5, and thus holds up and secures the cover in place. The contacting edges of the cover 5 and of the fixed portion of the top in front, it will be understood, are suitably beveled or flanged, so as to afford a proper support for the coverand avoid any strain on its hinges, though it is believed that owing to its lightness the latch alone is sufficient to hold it up.

By preference the grate E hereinabove- This latch is mentioned is made up of separate bars, so the same may be replaced or mended more easilyin case of breakage. The several bars of which the said grate is composed have their ends bent in opposite directions somewhat like an elongated S, and in this way will have a sufficient space left between all of them when they are brought together. They are supported inside the stove by end bars M M when the stove is in its normal position; but when the stove is set on end, as represented in Fig. 3, they are then caught and held at one end between the bar M and a small flange M projecting inward from the stove-bottom, and their other end is brought to bear against the stove-top on the inside, near the smoke-outlet F.

The use and operation of the stove A will be understood withouta detailed explanation. When sinking a shaft, the stove is to be set upright, as shown in Fig. 1, and when drifting it is to be set on the end,with the bottom placed against the face of the drift, in the manner indicated in Fig. 3. The wood is put in through the aperture in the top when the stove stands upright and through the aperture in the plate 3 when the stove stands on end. In one case the fire is built on the top of the grate E. In the other case it is built on the under side of the grate E. The stovepipe G will run up straight when sinking the shaft. lVhen drifting, it will be provided with suitable elbows G and properly supported with wire or other hangers, as at G Fig. 3.

The stove hereinabove described will throw out enough heat to thaw the ground thoroughly and with a fair degree of rapidity where it is not frozen too hard or where one cannot afford to carry on operations in the most expeditions manner. Thus for the miner who cannot avail himself of the full and complete apparatus the stove alone will suffice. It will be found compact and convenient to handle, and as it affords means to carry the smoke 0K, thereby insuring proper ventilation, the miuerwill be enabled to work with comfort by its side. Where, however, it is desired to hasten forward the mining operations and do things on a larger scale, it will be necessary to use the second part of the apparatus hereinbefore mentionednamely, the-heater Bwhich is adapted to convey a blast of hot air under pressure to the stove A, and will assist it in promptly softening the various layers of frozen earth.

The air-heater aforesaid consists of a furnace marked 13, in which is mounted a retort orair-heating drum N, shaped like an inverted cone and located above a fire-grate P. The said furnace is preferably made of sheet-iron plates suitably riveted or bolted together and has double walls lined or filled in with asbestos or other substance which is a non-conductor of heat, as at B, Fig. 1. It is provided with the usual door B", ash-pit B, smoke-stack B and other accessories. The top of it, B, is detachable and is secured to the sides by iron bands B and bolts B as shown in Figs. 1 and 2. The retort or drum N is held up centrally within the furnace or heater B by means of supporting-bars N that are caught between the bolted bands 13 This retort or drum, it will be seen, is well adapted by its shape to absorb all the heat emanating from the fire built on the grate P under it, and also from the smoke that passes up along its sides and thence escapes through the smoke-stack B The retort or drum N is supplied with air under pressure by means of an air-pump Q, connected with it at its lower end by a pipe or series of pipes Q passing through one side of the furnace B. Any type or style of air-pump may be used, although the form selected and represented in the drawings will answer the purpose well. As shown, the piston-rod Q of the pump Q can easily be worked by hand with a crank-shaft Q to which are attached a balance-wheel Q and a hand-crank Q. A pulley and belting could be substituted for the hand-crank where it would be desirable to work the pump by power instead of by hand. The pump itself, it will be observed, could also be replaced by a fan, or blower, or bellows, or some other aircompressing appliance, which would then supply the fresh air to the retort. All such changes are within the scope of my invention. After being heated in the retort or drum N the air is let out through a pipe R, that also passes through one side of the furnace B and connects the upper end of said retort or drum with an extensible series of jointed or flexible pipes S S The pipes S S in turn bring the hot air to the stove A, which it enters through an opening T, provided in one end of the stove-top 5 in line with the opening for the stovepipe G, which is located at the opposite end of said stove-top, as shown in the several figures of the drawings.

The pipes marked S are made of metal and are to be covered with asbestos to prevent the cooling of the air passing through them. They are connected to one another by means of couplings S S that fit one into the other, and through which is passed a bolt or pivotpin S as shown in detail in Fig. 5. The joints of the several pipes S are thus rendered flexible or pivotal, and will therefore allow said pipes to move freely in different directions, so that they may extend out or reach up or down, as needed. The pipes marked S are made of rubber or canvas, also wrapped with asbestos, and of course are flexible of their very nature. Either the pipes S or the pipes S could be used alone, if desired, but there are instances when they can be used with advantage together. In such cases they are united by any suitable coupling, such as is shown at S, Fig. 3. A nipple S is pro vided on either the pipes S or the pipes S where they connect with the stove A, the same fitting tightly in the hole T. It will now be seen that as the forced draft of hot air from the retort enters the stove it will fan the ICC flames of the fire burning in it and direct the same against the frozen earth, which will thus be readily softened and loosened. The hot air besides will intensify the heat and penetrate where the flames may not reach, so that a larger area of ground will be thawed out in a given time, and as the hot air comes in at one end and the smoke goes out at the opposite end this also will contribute in causing the fire to burn brightly and operate to despatch the work. The course of the hot air and smoke is indicated by the arrows in Fig. 3.

It will be further observed that the airheater can also be used alone for thawing the earth, if desired. It is a peculiarity of my improved thawing apparatus that its componentv parts are disconnectible from each other andmay be used singly as well as in combination, as preferred. Thus the stove can be used alone and so can the air-heater, or the two can be used together. When the hot air alone is depended on to thaw the ground, it is best to apply it through the stove, though no fire is made. The stove will then act as a hood and confine and reflect the heat toward the point to be thawed out. In such a case the opening F for the smoke is stopped to prevent the hot air from escaping through it. The opening T for the hot air is likewise stopped when the stove alone is used, so that the smoke will not pass through it and remain in the shaft or drift where work is going on. The apparatus, whether used as a whole or in part, will be found to greatly facilitate the work of digging or excavating by properly preparing the ground for it.

Instead of the retort or drum N hereinabove described I sometimes use a series of pipes to heat the air with which the apparatus is supplied. These pipes run on all sides of the furnace and are connected with one another in a continuous coil. At the back and sides of the furnace they go all the way down; but at the front there is left an opening in which to put in Wood or coal to fire up in order to heat the air in them. The effect is the same as when a retort or drum is used.

WVhat I claim as my invention, and desire to secure by Letters Patent of the United States, is

1. In an earth-thawing apparatus, a stove adapted to be operated either in a horizontal or vertical position, a grate therefor, and means for supporting said grate in two positions in the stove to hold the fuel in either position of the stove, substantially as described.

2. In an earth-thawing apparatus, a stove having a filling-opening in each of two sides thereof at an angle to each other, a grate, and

means for supporting said grate in position to receive the fuel from either of said fillingopenings, substantially as described.

3. A bottomless stove comprising a top having a suitable filling-door, and a smoke-opening near one end, a side adjacent said smokeopening having a fi1ling-door, a grate, and means for supporting said grate in position to support the fuel whether the stove is placed on its bottom or with said side uppermost, said stove having a suitable draft-opening near the end opposite the smoke-opening, substantially as and for the purpose specified.

4:. In an earth-thawing apparatus, the combination of a stove adapted to be operated in either a horizontal or a vertical position, a grate therefor, and means for supporting said grate in two positions in the stove to hold the fuel in either position of the stove, and means for supplying heated air under pressure to the stove, substantially as described.

5. In an earth-thawing apparatus, a stove comprising a top and sides detachably secured together, said top and one side having suitable filling-openings, a detachable grate, means for supporting the grate in either of two different positions whereby it is enabled to support the fuel whether the stoveis placed in a horizontal position or on end, said stove having suitable smoke and draft openings, substantially as described.

In testimony whereof I have hereunto set my hand and seal.

ALVIE HEITZELMANN. [L. s.]

In presence of- FRANCIS A. QUINN, A. H. STE. MARIE. 

